Caesar cipherCaesar cipher, is one of the simplest and most widely known encryption techniques.
The transformation can be represented by aligning two alphabets,
the cipher alphabet is the plain alphabet rotated left or right by some number of positions.
When encrypting, a person looks up each letter of the message in the 'plain'
line and writes down the corresponding letter in the 'cipher' line. Deciphering is done in reverse.
The encryption can also be represented using modular arithmetic
by first transforming the letters into numbers, according to the scheme, A = 0, B = 1,..., Z = 25.
Encryption of a letter x by a shift n can be described mathematically as
Plaintext: maxim

cipher variations:

nbyjn

oczko

pdalp

qebmq

rfcnr

sgdos

thept

uifqu

vjgrv

wkhsw

xlitx

ymjuy

znkvz

aolwa

bpmxb

cqnyc

drozd

espae

ftqbf

gurcg

hvsdh

iwtei

jxufj

kyvgk

lzwhl

Decryption is performed similarly,
(There are different definitions for the modulo operation.
In the above, the result is in the range 0...25. I.e., if x+n or x-n are not in the range 0...25,
we have to subtract or add 26.)
Read more ...Atbash CipherAtbash is an ancient encryption system created in the Middle East.
It was originally used in the Hebrew language.
The Atbash cipher is a simple substitution cipher that relies on
transposing all the letters in the alphabet such that the resulting alphabet is backwards.
The first letter is replaced with the last letter, the second with the second-last, and so on.
An example plaintext to ciphertext using Atbash:

Baconian CipherTo encode a message, each letter of the plaintext is replaced by a group of five of the letters 'A' or 'B'.
This replacement is done according to the alphabet of the Baconian cipher, shown below.

Affine CipherIn the affine cipher the letters of an alphabet of size m are first mapped to the integers
in the range 0..m - 1. It then uses modular arithmetic to transform the integer that each plaintext
letter corresponds to into another integer that correspond to a ciphertext letter.
The encryption function for a single letter is
where modulus m is the size of the alphabet and a and b are the key of the cipher.
The value a must be chosen such that a and m are coprime.Considering the specific case of encrypting messages in English (i.e. m = 26),
there are a total of 286 non-trivial affine ciphers, not counting the 26 trivial Caesar ciphers.
This number comes from the fact there are 12 numbers that are coprime with 26 that are less than 26
(these are the possible values of a). Each value of a can have 26 different addition shifts (the b value)
; therefore, there are 12*26 or 312 possible keys.Plaintext: maxim

cipher variations:

nbyjn

lbszl

jbmpj

hbgfh

fbavf

dbuld

zbirz

xbchx

vbwxv

tbqnt

rbkdr

pbetp

oczko

mctam

kcnqk

ichgi

gcbwg

ecvme

acjsa

ycdiy

wcxyw

ucrou

scles

qcfuq

pdalp

ndubn

ldorl

jdihj

hdcxh

fdwnf

bdktb

zdejz

xdyzx

vdspv

tdmft

rdgvr

qebmq

oevco

mepsm

kejik

iedyi

gexog

celuc

aefka

yezay

wetqw

uengu

sehws

rfcnr

pfwdp

nfqtn

lfkjl

jfezj

hfyph

dfmvd

bfglb

zfabz

xfurx

vfohv

tfixt

sgdos

qgxeq

ogruo

mglkm

kgfak

igzqi

egnwe

cghmc

agbca

ygvsy

wgpiw

ugjyu

thept

rhyfr

phsvp

nhmln

lhgbl

jharj

fhoxf

dhind

bhcdb

zhwtz

xhqjx

vhkzv

uifqu

sizgs

qitwq

oinmo

mihcm

kibsk

gipyg

eijoe

cidec

aixua

yirky

wilaw

vjgrv

tjaht

rjuxr

pjonp

njidn

ljctl

hjqzh

fjkpf

djefd

bjyvb

zjslz

xjmbx

wkhsw

ukbiu

skvys

qkpoq

okjeo

mkdum

ikrai

gklqg

ekfge

ckzwc

aktma

ykncy

xlitx

vlcjv

tlwzt

rlqpr

plkfp

nlevn

jlsbj

hlmrh

flghf

dlaxd

blunb

zlodz

ymjuy

wmdkw

umxau

smrqs

qmlgq

omfwo

kmtck

imnsi

gmhig

embye

cmvoc

ampea

znkvz

xnelx

vnybv

tnsrt

rnmhr

pngxp

lnudl

jnotj

hnijh

fnczf

dnwpd

bnqfb

aolwa

yofmy

wozcw

uotsu

sonis

qohyq

movem

kopuk

iojki

godag

eoxqe

corgc

bpmxb

zpgnz

xpadx

vputv

tpojt

rpizr

npwfn

lpqvl

jpklj

hpebh

fpyrf

dpshd

cqnyc

aqhoa

yqbey

wqvuw

uqpku

sqjas

oqxgo

mqrwm

kqlmk

iqfci

gqzsg

eqtie

drozd

bripb

zrcfz

xrwvx

vrqlv

trkbt

pryhp

nrsxn

lrmnl

jrgdj

hrath

frujf

espae

csjqc

asdga

ysxwy

wsrmw

uslcu

qsziq

ostyo

msnom

kshek

isbui

gsvkg

ftqbf

dtkrd

btehb

ztyxz

xtsnx

vtmdv

rtajr

ptuzp

ntopn

ltifl

jtcvj

htwlh

gurcg

eulse

cufic

auzya

yutoy

wunew

subks

quvaq

oupqo

mujgm

kudwk

iuxmi

hvsdh

fvmtf

dvgjd

bvazb

zvupz

xvofx

tvclt

rvwbr

pvqrp

nvkhn

lvexl

jvynj

iwtei

gwnug

ewhke

cwbac

awvqa

ywpgy

uwdmu

swxcs

qwrsq

owlio

mwfym

kwzok

jxufj

hxovh

fxilf

dxcbd

bxwrb

zxqhz

vxenv

txydt

rxstr

pxmjp

nxgzn

lxapl

kyvgk

iypwi

gyjmg

eydce

cyxsc

ayria

wyfow

uyzeu

sytus

qynkq

oyhao

mybqm

lzwhl

jzqxj

hzknh

fzedf

dzytd

bzsjb

xzgpx

vzafv

tzuvt

rzolr

pzibp

nzcrn

maxim

karyk

ialoi

gafeg

eazue

catkc

yahqy

wabgw

uavwu

sapms

qajcq

oadso

The decryption function iswhere a - 1 is the modular multiplicative inverse of a modulo m. I.e., it satisfies the equationThe multiplicative inverse of a only exists if a and m are coprime.
Hence without the restriction on a decryption might not be possible.
It can be shown as follows that decryption function is the inverse of the encryption function,Read more ...

ROT13 CipherApplying ROT13 to a piece of text merely requires examining its alphabetic
characters and replacing each one by the letter 13 places further along in the alphabet,
wrapping back to the beginning if necessary. A becomes N, B becomes O, and so on up to M,
which becomes Z, then the sequence continues at the beginning of the alphabet: N becomes A,
O becomes B, and so on to Z, which becomes M. Only those letters which occur in the English
alphabet are affected; numbers, symbols, whitespace, and all other characters are left unchanged.
Because there are 26 letters in the English alphabet and 26 = 2 * 13, the ROT13 function is its own inverse:

Polybius SquareA Polybius Square is a table that allows someone to translate letters into numbers.
To give a small level of encryption, this table can be randomized and shared with the recipient.
In order to fit the 26 letters of the alphabet into the 25 spots created by the table, the letters
i and j are usually combined.

1

2

3

4

5

1

A

B

C

D

E

2

F

G

H

I/J

K

3

L

M

N

O

P

4

Q

R

S

T

U

5

V

W

X

Y

Z

Basic Form:

Plain:

maxim

Cipher:

2311354223

Extended Methods:Method #1

Plaintext: maxim

method variations:

rfcor

wlhtw

bqnyb

gvsdg

Method #2Bifid cipherThe message is converted to its coordinates in the usual manner, but they are written vertically beneath:

m a x i m
2 1 3 4 2
3 1 5 2 3

They are then read out in rows:
2134231523Then divided up into pairs again, and the pairs turned back into letters using the square:

Permutation CipherIn classical cryptography, a permutation cipher is a transposition cipher in which the key is a permutation.
To apply a cipher, a random permutation of size E is generated (the larger the value of E the more secure the cipher).
The plaintext is then broken into segments of size E and the letters within that segment are permuted according to
this key.
In theory, any transposition cipher can be viewed as a permutation cipher where E is equal to the
length of the plaintext; this is too cumbersome a generalisation to use in actual practice, however.
The idea behind a permutation cipher is to keep the plaintext characters unchanged,
butalter their positions by rearrangement using a permutation
This cipher is defined as:Let m be a positive integer, and K consist of all permutations of {1,...,m}For a key (permutation) , define:
The encryption function The decryption function A small example, assuming m = 6, and the key is the permutation
:The first row is the value of i,
and the second row is the corresponding value of (i)The inverse permutation, is constructed by interchanging the two rows,
andrearranging the columns so that the first row is in increasing order, Therefore, is:
Total variation formula: e = 2,718281828 , n - plaintext length